Jenny Jones, BS, RLAT, CLAP
Animal Enrichment Coordinator
Animal Care Supervisor

Nesting material is a key component to allow rodents to exhibit one of  their most natural behaviors, nest building.  In the wild, mice build nests out of grass, hay, twigs etc.  It serves as the main source of their thermoregulation, a place to hide, a place for their pups, and place to sleep.  Research has shown that mice tend to build better nests with increased amount of nesting material in standard caging.  What is the appropriate amount?  What is too much nesting material?  What if husbandry technician cannot see the mouse inside the cage?  In the post, Jenny Jones explains the process implementing increased nesting material in her facility.

Our journey to increase nesting material inside all mouse cages has been long and challenging.  There was at least a year of piloting and internal studies before we started the progressive roll out across all our facilities.

Steps involved to make the change were:

1. Create Buy-in from Upper Management
2. Create Researcher Buy-In
3. Find and Source Materials
4. Retrain Husbandry Staff

While every step was essential to the implementation of this new practice, one essential step that I am going to focus on in this post was re-training our current staff to perform efficient health checks (daily cage side assessments) with the increased nesting material.

First, we anticipated that there would be some anxiety around the change. Because of this, we put a lot of effort into communicating all aspects of the process to our technicians.  It is really easy when you’re working on a project to forget that not everyone has the same background information as you and your team.  We used all staff meetings to update them on the beginning of the pilot. While, outlining both the why of regulatory requirements and how it improved animal welfare, we also explained potential challenges we anticipated and invited them to let us know if they felt there were additional challenges we overlooked. Acknowledging that it is a huge change and recognizing potential difficulties helped to show we were taking the potential disruptions to their workday seriously and weren’t just running into this willy nilly.  Many technicians were easily on board with just the possibility of improving animal welfare but some still had concerns.

The main concern technicians expressed was that they would miss sick cases while performing daily health checks. Some worried primarily from an animal welfare perspective and others were more concerned they might get in trouble or worse written up.  We worked to reassure everyone that our goal was to work through the process with individuals and not get anyone in trouble. Because we performed an internal study about missing health concerns and dead animals with the nesting material aided the continual concerns. link

For husbandry, management worked to set up clear and consistent expectations.  I personally worked with our trainers to help establish new health check protocols.  We worked through a flow chart of assessment starting with the least disruptive all the way through opening and removing the cage.  We have continued to re-evaluate our health check processes including changing some techniques that were originally proposed as optional to mandatory.

We communicated the new health check guidelines with a full PowerPoint in an all-staff meeting.  In short, less formal talks to our small team meetings and offered individual assistance as needed.  The big picture message was to reframe the thoughts of “I can’t see” to “I am looking at the whole cage environment to assist my assessment.”

Our team created some really beautiful visual aids to further assist our technicians with assessing that cage environment.  It includes comparisons of nest quality and cage organization, and potential signs of fighting.  These signs that were printed, laminated, and hung on every laminar flow hood also showed a time progression of nest building.

It can be very hard to fight against the confirmation bias inherent in everyone.  The technician who found one mouse dead inside the nest will eagerly share that story every time the topic comes up.  As the one trying to implement a big, positive change, recognize that you will not win everyone over even with your pretty PowerPoints and data and evidence, but it will still be worth it in the end.